The present invention relates to an exterior rearview mirror for mounting on a vehicle and, more particularly, to an extendable exterior rearview mirror for mounting on a vehicle which can be extended when the vehicle is being used for towing, for example towing a trailer, camper, or the like.
Until recently, towing mirrors included a fixed support or frame, which was rigidly mounted to the vehicle body, and a reflective element supported on and spaced from the vehicle body by the support or frame to provide rearview viewing of the towed object. For example, U.S. Pat. No. 3,119,591 to A. J. Malecki illustrates a typical rigidly mounted towing mirror assembly. However, these fixed extended rearview mirror assemblies increase the width of the vehicle often hampering normal maneuvering through passages including garage door openings, drive-through services, and the like. Furthermore, they are more vulnerable to being damaged or causing damage than conventional exterior rearview mirrors especially when used by an inexperienced driver. In some cases, the width of the vehicles was increased beyond the maximum width allowed by conventional vehicle transport trucks which deliver the vehicles to the dealership. Therefore, these mirror assemblies often required installation at the dealership which ultimately increased the cost of the vehicle.
More recently, several extendable exterior rearview mirrors have been developed. For example, in U.S. Pat. No. 5,513,048 to Chen and U.S. Pat. No. 5,489,080 to Allen, extendable rearview mirrors are disclosed which include telescoping members. The position of the mirror subassembly, which includes a reflective element and reflective element housing, is fixed in position by threaded fasteners, which require tools for adjustment. However, these assemblies tend to increase the vibration of the mirror assembly especially when the mirror subassembly is in the outboard position. This increased vibration is particularly problematic in mirror assemblies that incorporate mechanical or electrical actuators since they increase the weight of the mirror casing. Other solutions have included providing nesting mirror reflectors with one of the mirror reflectors supported in a housing that is extendable from the mirror casing, such as described in U.S. Pat. Nos. 4,998,812 and 4,907,871 to Hou. While these assemblies incorporate a single arm mounting arrangement, the assembly is complicated and requires a dual reflection system that ultimately increases the cost of the assembly, as well as the weight of the mirror casing. Heretofore, commercially available exterior mirrors have used a twin arm arrangement in order to increase the stiffness of the mounting attachment, such as disclosed in U.S. Pat. No. 5,483,385 to Boddy. Such twin arms provide support to the mirror casing in a manner that minimizes mirror reflector vibrations when the vehicle travels on roads. However, use of such twin arm arrangements dictates a relatively large assembly with multiple mounting components, which increases material cost and assembly time. Hitherto, use of a single arm extendible mirror assembly has not met with commercial success because of the reduced stiffness associated with prior art designs which result in increased vibration.
Consequently, there is a need for an extendable rearview mirror assembly that can provide for an extended field of view when towing and yet can be retracted to a normal operating position where it does not hamper maneuverability of the vehicle. In addition, the extendable rearview mirror assembly should have minimal impact on the vibration characteristics of the mirror assembly and be relatively easy to adjust between non-towing and towing positions without the need for tools.
Accordingly, the present invention provides an improved vehicular extendable exterior rearview mirror assembly which is especially suitable for use on vehicles when towing. The exterior rearview mirror assembly is adjustable to a plurality of viewing positions between a normal non-towing use position and a fully extended position, allowing an adjustable field of view to the rear of the vehicle. Additionally, the mirror assembly may include a break-away assembly to permit the mirror assembly to be folded to a break-away position in the event the mirror assembly strikes an object. Furthermore, the mirror assembly may include a power fold mechanism which allows the mirror subassembly to be folded or retracted to a folded position when the vehicle is driven into tight spaces, for example parking garages and the like.
According to one aspect of the invention, the extendable exterior rearview mirror assembly includes a mounting bracket, a mirror subassembly, a clamp, and a support which is mounted for pivotal movement on the mounting bracket between a normal operating position and a folded, break-away position. The support extends laterally outward from the mounting bracket when the mirror subassembly is mounted to the vehicle and the support is in its normal operating position. The support extends into the housing of the mirror subassembly, where the clamp is positioned to mount the mirror subassembly onto the support. The clamp applies a force to urge frictional engagement between the support and the housing to limit movement of the mirror subassembly along the support but permits selective movement of the mirror subassembly along the support to one of at least two viewing positions when a force of sufficient magnitude is applied to the subassembly to overcome the friction between the support and the housing.
In one aspect, the support comprises a single support arm. In other aspects, the mirror assembly further includes a load distributing member, which together with the clamp urges frictional engagement between the support and the housing. In another aspect, the support moves relative to the load distributing member when the mirror subassembly moves along the support.
In yet other aspects, the clamp includes a passage, such as a longitudinal passage, in which the load distributing member is positioned. At least a portion of the support extends into the passage to be urged by the clamp into frictional engagement with the housing. In further aspects, the load distributing member comprises an elongate member having a longitudinal extent extending along at least a portion of the support. Preferably the load distributing member comprises an arcuate-shaped elongate member. The support arm has an arcuate bearing surface and a planar side with a plurality of line bearing surfaces, with the load distributing member contacting the arcuate bearing surface and urging the line bearing surfaces to frictionally engage the housing.
In further aspects, the support arm comprises a composite elongate body which includes an elongate webbed member having the arcuate bearing surface and a plate bearing member which provides the line bearing surfaces.
In other aspects, the housing includes a mirror casing, with the clamp urging the support into frictional engagement with the mirror casing. For example, the mirror casing may include a casing wall which defines a cavity, with the reflective element supported in the cavity by the casing wall. The clamp urges the support arm into frictional engagement with the casing wall.
In yet further aspects, the mirror assembly includes a positioning device, which supports the reflective element on the casing wall. For example, the positioning device may comprise an electrical actuator.
In another aspect, the extendable exterior rearview mirror assembly further includes a driver assembly which selectively moves the mirror subassembly along the support arm.
According to another form of the invention, an extendable exterior rearview mirror assembly includes a mounting bracket, a mirror subassembly, and a support. The mirror subassembly includes a housing, a reflective element, and an actuator. The housing includes a mirror casing. The support is mounted to the mounting bracket and extends from the vehicle in a laterally outward direction and into a housing of the mirror subassembly when the mirror assembly is mounted to the vehicle. The mirror assembly further includes a clamp which mounts the mirror subassembly on the support. The clamp applies a force to the support to urge frictional engagement between the support and the mirror casing to limit movement of the mirror subassembly along the support. The mirror slides along support to one or more extended viewing positions when a force is applied to the mirror subassembly in the laterally extending direction sufficient to overcome the friction between the support and the mirror casing.
In further aspects, the mirror casing includes a back wall. The actuator preferably supports the reflective element on the back wall. The clamp applies a force which urges the support into frictional engagement with the back wall. Preferably, the clamp includes a load distributing member which urges the support into frictional engagement with the back wall and, further, distributes the force from the clamp along the length of the support positioned in the clamp. For example, the support preferably includes an arcuate bearing surface and a planar bearing surface. The load distribution member preferably comprises an arcuate elongate member which engages the arcuate bearing surface of the support arm and urges the planar bearing surface of the support into frictional engagement with the exterior portion of the back wall of the mirror casing.
In yet further aspects, the arcuate elongate member forming the load distributing member may include a plurality of inwardly projecting elongate ribs, which contact the arcuate bearing surface of the support. In addition, the arcuate member may include a plurality of exteriorly positioned elongate ribs, which are contacted by the clamp to mount the mirror subassembly on the support. Preferably, the exteriorly positioned elongate ribs are offset from the inwardly projecting elongate ribs which thereby form discrete spring members in the load distributing member.
In other aspects, the housing further includes a cover which is coupled to the mirror casing and defines a cavity into which the support extends for frictionally engaging the mirror casing.
As will be understood, the exterior rearview mirror assembly of the present invention provides numerous advantages over prior known extendable rearview mirror assemblies. The exterior rearview mirror assembly incorporates a single support arm for mounting the mirror subassembly to a vehicle on which the mirror subassembly can be moved to a plurality of extended positions to provide an adjustable extended field of view and which can be quickly retracted to a normal operating position where it does not hamper the maneuverability of the vehicle or increase the width of the vehicle. In addition, the exterior rearview mirror assembly can be adjusted either manually or by the use of a driver, which can be operated by a remote control within the vehicle cabin. Thus, the single arm extendable mirror assembly of the present invention provides a compact assembly with excellent vibrational performance when mounted and used on a vehicle. Hitherto, such excellent vibrational performance is achieved and has been achieved commercially such as by using twin arm extendable mirror assemblies such as described in U.S. Pat. No. 5,483,385 to Boddy. Achieving an acceptable and user appreciable or enjoyable exterior mirror assembly performance when the assembly is mounted to the vehicle while using a single arm is a significant advantage as this allows a more compact design and thus, a more consumer appreciable or appealing design.
These and other objects, advantages, purposes and features of the invention will become more apparent from the study of the following description taken in conjunction with the drawings.